Excavator



May 7, 1935.

H. SIE BERT EXCAVATOR Filed Jan. 27,1933

Inventor (0. 5.. W4. dttorney Patented I 7, I

I Umr.ap srArEs PATENT orrlcs EXCAVATOR Heinrich Siebert,Dnisburg,'Germany, assignor to Demag Aktieng'esellschait, Duisburg,Germany Application January 27, 1933, Serial No; 653,791 In GermanyFebruary 5,1932

8 Claim.

also connected to gearing for directing the shovel,

whereby when the extension of the hoisting cable is gripped, the shovelcan be swung on the swing: mg of the haft-member while retaining itsapproximate position in space, the shovel being tipped and thus emptiedwhen the extension of the hoisting cable is released.

The mechanism for directing the shovel consists essentially of a guidingquadrilateral which approximates to a pivoted parallelogram; thisquadrilateral consists of the braking or gripping device, the lower armof the haft-member, the shovel and the extension to the hoisting cable.

The instroke excavator according to the invention has the advantage thatnotwithstanding the range of movement of the shovel, two cables are inpractice suflicient, namely the hoisting cable and the drag cablehereinafter described, that is to say there is the minimum number ofcables and an extremely simple cable guide. Notwithstanding thissimplification of construction, the shovel can be emptied in anyposition and accidental tipping of the shovel is eflectively avoided.

The invention is diagrammatically illustrated by way of example in theaccompanying drawing, in which Figure 1 illustrates the method ofcontrolling the shovel.

Figures 2 and 3 illustrate by way of example two constructions of thecontrolling apparatus. Figures 4 and 5 show two operative positions ofthe excavator according to the invention.

Referring to Figure 1 of the drawing, the haft member 3 of the shovel isrotatable about the pivotal axis 2 of the jib l of an instrokeexcavator. It is drawn by the drag cable 4 towards the excavator, whilethe haft-member I is moved by the hoisting cable 5 in the oppositedirection. The hoisting cable 5 extends beyondthe pulley 6 mounted atthe upper end of the haft-member 3 and is connected to the shovel I;this extension of the cable 5 is numbered in. The extension 5a may beheld fast by a braking or-clamping member 8 provided on the jib I. Thus,if the haft-member 3 is moved, the shovel I maintains its approximateangular disposition in space. This is due to the fact that the shovel iscarried by a. pivoted quadrilateral formed by the lower arm of thehaft-member 3, the top edge of the side of the shovel I, the extension5a of the hoisting cable and that part of the extension of the jibbetween the pivotal axis 2 and the braking or clamping member 8. If thebraking or clamping member 8 is released, the shovel I can be tipped bymeans ,of the cable 5, and turns about the axis l8 until it strikesagainst the stop I.

Figures 2 and 3 illustrate in detail two constructions of braking deviceaccording to the invention. The reference numerals are for the most partthe same as those in Figure 1. In Figure 2, the hoisting cable 5 issecured to a bell crank lever l0, which rocks about an axis 2, for

example the axis of the haft-member 3, but independently of thehaft-member itself. A cable, chain or belt I 3, extends from the lowerarm of the bell crank lever III to a drum H, which drum is provided witha brake, the brake band being numbered IS. The brake band I5 is underthe influence of a pressure medium cylinder and piston it, which mayoperate for example with compressed air or steam, or water underpressure, or it may be controlled by an electro-magnet or by hand. Thebell crank lever I is connected to the shovel 1 by a cable or rod H,which is connected to the shovel at II. If the brake holds fast thelever l0, and the drag cable 4 is slackened while the hoisting cable istensioned, the haft-member 3 is rocked by the hoisting cable 5, whilethe shovel l retains its approximately horizontal position because theparts l0, 3, i and II form a pivoted parallelogram. If on the other handthe brake I5 is .released, the shovel I can be moved relatively to thehaft-member 3.

The construction according to Figure 3 differs from that according toFigure 2 in that the lever I0 is replaced by a sector H, the hoistingcable 5 passing over the arc Ila of the sector while the cable l3 whichextends to the drum l4 lies on the channel "b. The method of operationis substantially the same as that of the construction according toFigure 2.

Figure 4 illustrates the shovel shown in Figure 2 in the positionreached near the end of the movement along the pit being excavated. Thebrake I 5 is first released, the drag cable I is then tensioned, whilethe cable 5 is slackened. The shovel is thus caused to move inwardly andto be filled.

The haft member 3 is now moved outwardly by the winding in of the cable5 and the slackening oi the drag cable 4. The lever I0 is first securedby the brake band ll. If the bait-member 3 is rocked, the mechanismwhich determines the disposition of the shovel consisting of the parts3, I, Iii and ii causes the shovel to retain approximately its angulardisposition in space, so that the final position is more or less asshown in Figure 5. The shovel does not rotate with the hattmember I andthus the earth or other material ls prevented from falling out of theshovel when the hart-member 3 is moved. To empty the shovel I in theposition illustrated in Figure 5, which need not be the extremeposition, the brake band i5 is loosened so that the shovel I may bemoved about the axis [8 to abut against the stop it by tensioning thecable 5.

Figures 1, 2 and 3 illustrate various modifications in construction ofthe braking or like device but it will be understood that the inventionis not limited to the constructions shown which are given merely by wayof example.

The important point is that the movement of the shovel relatively to theheft-member is in all positions under the control of the hoisting cable5.

I claim:

1. An instroke excavator comprising a jib, hart member supported by androtatable upon the said jib, a shovel movable relatively toand supportedby the haft member, a braking element adjustable upon the said jibindependently of the said haft member, a hoisting cable connected withthe braking element and engaging the bait member, and a link between thebraking element and the shovel such that the braking element beingretained in fixed relation to the jib the bait member may be swung bythe hoisting cable while the shovel retains its angular disposition inspace.

2. An instroke excavator comprising a jib, a bait member pivoted at apoint intermediate its ends upon the jib, a braking element upon saidjib to which the bait member is relatively rotatable, means upon saidjib for operating said braking element, a shovel pivoted to one end ofthe said haft member, a connection between the braking element and theshovel at a radius from the pivotal point of the shovel, a drag cableconnected to said heft member, and a hoisting cable connected to thesaid braking element and engaging the haft member.

3. An instroke excavator comprising a jib, a bait member pivoted at apoint intermediate its ends upon the jib, a braking element rotatableabout the pivot of the bait member upon the said jib, a brake mechanismupon the said jib controlling the rotation of the braking element, a

shovel pivoted to one end of the said hart member, a link connectedbetween the braking element and the shovel at a radius from the pivotalpoint of the shovel, a drag cable connected to said hart member, and ahoisting cable connected to said braking element and engaging the haftmember.

4. An instroke excavator according to claim 3, in which the brakingelement is subjected to the control of the braking mechanism through aconnection which engages the braking element with a leverage distinctfrom that applied by the braking element through the link to the shovel.

5. An instroke excavator comprising a jib, a haft member movablerelatively to the said jib, a shovel movable relatively to the baitmember, braking means upon the jib, mechanism for controlling themovement of the shovel including an element in extension of the hoistingcable and the said braking means whereby when the said element is brakedby the braking means and the haft member is swung the shovel may becorrespondingly moved while retaining its angular disposition in spaceand may be tilted when the said element is released by the brakingmeans.

6. An instroke excavator according to claim 5, in which the mechanismdirecting the shovel comprises a quadrilateral linkage consisting of thebraking means, the hatt member, the shovel and the said element.

7. An instroke excavator with mechanism for directing the shovel,including a shovel hart to which the shovel is pivoted, a hoisting cableoperatively linked or coupled to the shovel at a position distant fromthe pivotal axis to permit the hoisting cable to be used for tipping theshovel, and a braking device which when operative restrains the shovelfrom tipping and causes it to remain approximately in the same angulardisposition in space when the bait swings.

8. An instroke excavator comprising a jib, a shovel, a directingmechanism inclusive of a haft member pivoted to the jib and having theshovel pivoted thereon and by which the shovel is directed a hoistingcable, a shovel control member associated with, but movableindependently of, the haft member, and a braking device, the saidhoisting cable being connected with the control member which is linkedor coupled to the shovel for the tilting of the shovel by the hoistingcable and the braking device being applied to the said control member sothat when operative it retains the shovel approximately in the sameangular disposition in space when the haft member swings.

HEINRICH SIEBERT.

